Online Monitoring for Power Cables in DFIG-Based Wind Farms Using High-Frequency Resonance Analysis

Abstract

Increasing demand for renewable energy has led to a rapid growth of doubly fed induction generator (DFIG)-based wind farms around the world. As a critical component of the DFIG-based wind farms, online monitoring of the connected transmission cable is essential to maintain the reliability of the entire wind power plant. A novel online monitoring method for power cables in DFIG-based wind farms using high-frequency resonance (HFR) analysis is proposed in this paper. The HFR in wind farms due to the interaction between the DFIG unit and the connected cable is firstly modeled and the relationship between the HFR frequency and cable ageing severity is analyzed. An ageing severity estimation algorithm is then proposed based on adaptive hill climbing and particle swarm optimization (AHC&PSO). Simulations for wind farms with both the LCL and L filter are conducted to validate the proposed method. Effective online monitoring and accurate ageing severity estimation of the cables are achieved in the simulations under various operation conditions considering DFIG parameter deviations. Compared with existing approaches, the proposed method provides a superior online monitoring approach to accurately evaluate the ageing state of power cables in wind farms quantitatively with no need of extra monitoring sensors.